1. Field of the Invention
The present invention relates to a portable radio communication apparatus including a housing, and in particular, relates to a potable radio communication apparatus provided with a part of the housing operating as an antenna.
2. Description of the Related Art
Recently, portable radio communication apparatuses such as cellular phones have been increasingly made smaller in size and thinner. In addition, the portable radio communication apparatuses have been not only used as conventional cellular phones but also transformed to data terminal apparatuses for transmitting and receiving E-mails and for viewing web pages through the WWW (World Wide Web). Due to this, liquid crystal displays have been made larger in size. In these circumstances, folding cellular phone terminals, which are considered to be suited to make the portable radio communication apparatuses smaller in size and make the liquid crystal displays larger in size, have been spread as disclosed in the following publications:
(a) Japanese Patent Laid-open Publication No. 2001-156898;
(b) Japanese Patent Laid-open Publication No. 2002-084355;
(c) Japanese Patent Laid-open Publication No. 2002-335180;
(d) Japanese Patent Laid-open Publication No. 2002-299931; and
(e) Japanese Patent Laid-open Publication No. 2002-516503.
However, an antenna for use in the conventional portable radio communication apparatus requires an antenna-dedicated electrically conductive part, and then, requires a space occupied by the conductive part. Due to this, the portable radio communication apparatus cannot be made thinner. Besides, if the antenna is constituted by using a printed wiring board or the like, the material cost is required for the elements, thereby disadvantageously increasing the manufacturing cost thereof.